Conventions on Drug Names
Conventions re: drug names especially long acting opioids
- Generic prescribing of modified release opioids – in accordance with BNF advice (see attachment)
- Brand name prescribing when the pharmacokinetic profiles of different brands of the same opioid differ widely, e.g. rapid acting fentanyl products (Abstral®, Effentora®)
Good practice points
- Dual labelling of dispensed opioids, noting both the generic medicine name and the brand medicine name on the patient’s medicine (dispensed) label e.g. Morphine Sulfate modified release 10mg tablets (Morphgesic SR).
- Provide verbal and written information on strong opioids to patients and carer which includes:
- Explanation of the treatment plan – reason for use and side-effects
- Explanation of the different opioid forms: long acting and quick acting
- Explanation of the generic and brand names of opioids
- How, when and how often to take opioids
- Consistency with medicine forms/preparations dispensed for individual patients in the community
- Inclusion of the indication for the medicine on the dispensed medicine label.
- Inclusion of the medicine form on prescriptions and instruction to administer charts for opioids e.g. OxyNorm® is a brand name for oral oxycodone liquid and capsules, but it is also the brand name for oxycodone injection. Where the form is included with the medicine name this may help to prevent a selection error e.g. oxycodone injection; oxycodone capsules/liquid. (Note: oxycodone injection is the only medicine form suitable for subcutaneous/injectable use).
Points of information
- Various terms and abbreviations are used to show a medicine is a modified release preparation e.g. long acting (LA); sustained release (SR); prolonged release (PR); controlled release (CR); modified release (MR); XL; chrono; retard.
- The generic term is modified release
- Modified release preparations can be used to reduce the dosing frequency and to reduce fluctuations in drug plasma concentrations.
- It is important to use the correct preparation for the prescribed dose and frequency
- The duration of action of the modified morphine products MST Continus ®; Morphgesic SR® and Zomorph is 12 hours. The duration of action of MXL® is 24 hours.
- Opioids have been identified as “high risk” medicines. The following are examples of measures that may decrease risk associated with opioids:
- Using the ordinary release product when the modified release preparation is prescribed means the patient has a much higher level of drug initially and sub therapeutic levels later on. This may lead to increased side effects when levels are high and less effect when levels are low.
- Staff should be familiar with the range of oral opioid products available and the usual frequencies in which they are prescribed and administered.
- Treatment guidelines should be available to support the use of oral opioids where they are used routinely.
- High strength opioids should not be stored in any clinical area in which they are not routinely used.
- Information on dose conversions between opioids medicines should be available.
- The inpatient instruction to administer chart must be the primary reference source for all prescriptions.
Dorothy McArthur 14th November 2012 on behalf of SPCPA
Why doesn't the BNF recommend brand-name prescribing for all modified-release preparations?
The MHRA recommends that all modified-release preparations should be prescribed by their brand name.
The BNF warns against changing brands only where there is the possibility of significant clinical impact (e.g. loss of clinical control or increased risk of adverse effects). In many instances, variation that results from non-bioequivalence is likely to have a smaller effect than other factors that determine absorption and distribution of the drug (e.g. not taking the medicine exactly on time and varying the time of taking the medicine with respect to food). For these reasons the BNF does not highlight the need to keep to the same brand for every modified-release drug.
Why does the BNF not recommend brand-name prescribing of modified-release opioids?
The BNF has not seen any evidence to indicate that switching between brands of modified-release opioids that have the same release profile (e.g. between different brands of 12–hourly oral morphine, or between different brands of fentanyl patch) alters the therapeutic effect. Furthermore, when used in accordance with the product licence, there are no grounds for a clinical difference between brands of fentanyl patch.
A suggestion has been made that brand-name prescribing of opioids should be adopted on grounds of safety. However, the BNF is not clear why modified-release opioids should be treated differently to other drugs commonly associated with medication errors (e.g. carbamazepine), or, indeed, other drugs in general. We have not seen any evidence to show that brand-name prescribing of modified-release opioids would have a significant impact on the incidence of medication errors associated with these preparations—if users of the BNF know of such evidence, we would be pleased to consider it.
Extracted from BNF online site 30/10/12